Swelling in Healthy Athletes

After competing as a figure athlete for almost 8 years one of the most common concerns I have heard from aesthetic athletes is at least one episode of random swelling somewhere on their body (not due to trauma).  I also have encountered this symptom many times in the hospital setting as a medical student.  In this setting we typically refer to it as edema.  If an attending physician or resident would ask me about causes or treatment my response would appropriately start with differentiating transudative vs. exudative causes.  I would talk about changes in capillary permeability and oncotic pressure.  Well, that is fine to show the docs I am not an idiot, but I try not to talk to my patients with the same language.  I try to relate and make sure they clearly understand their medical issue.  I would like to attempt to talk to athletes about this phenomenon the same way with an added twist that I am NOT going to address the serious illnesses/pathologies.
If an unhealthy person has swelling, my mind primarily rushes to which organ is damaged?  I have a complete differential for vascular/heart vs. liver vs. kidneys.  In a healthy person I think two things: salt/water imbalance or venous valve insufficiency.
First, let me share my definition of swelling.  Swelling is what happens when water gets trapped between the skin and tissues such as muscles and organs.  In healthy athletes it would most commonly occur in the legs, hands, belly/hips.
Now, let me address the two common causes in healthy athletes. 
Salt/Water Imbalance
Our bodies like to be balanced when it comes to concentration of salt.  Too little is just as bad as too much.  We have many sensors in our brain and kidneys to sense if this balance is off.  In a healthy person, the kidneys will not allow water to exit the body as urine if the salt in the tissues is too high.  This is because the body is trying to get that healthy concentration of salt and the only way it knows how to do that is keep the water inside.  So, let’s say you have been eating a very low sodium diet for several weeks in a row.  This does not mean you are necessarily hyponatremic (low salt in the blood).  You may be in the low-normal range which is healthy and fine.  If suddenly you intake a large amount of salt in one day, your body tries to adjust quickly to accommodate the increased concentration and urine output decreases and water starts shifting to the spaces between your skin and tissues for storage.  Even if you drink gallons and gallons of water, it takes time for the dilution process to take place, so you may STILL experience this swelling.  The amount of swelling is based on the amount of salt you intake. Water will help in the long run of course, but not as quickly as you might think.  The primary treatment for this type of swelling is to decrease the intake of sodium. 
Venous Valve Insufficiency
The second most common cause of swelling in healthy athletes is venous valve insufficiency.  This means the valves that help push the blood back to the heart from the veins in the body are not properly working.  Because the veins cannot pump the normal amount of blood back to the heart, this can cause swelling in the lower legs.  So, what causes this venous valves to not work?  With every step you take this helps the valves to pump blood inward and upward.  So during normal walking, the pressure in the venous system is about zero.  Right after you stop, that standing pressure is still pretty low.  The artery blood then slowly fills the veins.  Now the only pressure on the venous system is the hydrostatic pressure of a column of blood that really is only as high as the next competent valve.  If those valves fail, then the pressures do not change along this column from the head up to the heart.  So, now the pressure is high even when walking (remember I said it should be zero!)  This leads to venous congestion!
 It is important to understand that venous valves are made of collagen.  Just like collagen in other areas of the body, as you age you lose the ability to generate new collagen fibers which leads to a decrease in elasticity.  A decrease in elasticity in the valves equals more insufficiency.  And some people may genetically just have weaker collagen in the venous valves. 
There are a few more treatment options for this cause of swelling compared to the salt/water imbalance issue.  You can try compression stockings.  There are a variety of compression strengths.  For purposes limited to this discussion I recommend the ones that are about 30-40mmHg.  If those are uncomfortable of course get ones with less compression.  I do not recommend a higher level. Those are typically reserved for post-surgical purposes.  Another treatment option is to the raise the legs for about 30 minutes 3-4 times per day.  The legs need to be ABOVE the heart for maximum effectiveness.  For those that experience swelling while traveling I recommend the following tips:
– Drink plenty of water while in the air
– Get up and stretch/stand at least once per hour of flight
– Point and flex your feet, and bend your knees from time to time
– Wear loose-fitting clothing
– Wear shoes with shape and support such as tennis shoes instead of flip flops
– Do not smoke or drink alcohol before flying (doubt this applies to athletes, but just in case!) – even in celebration after a competition know it could increase your chances of swelling on the flight back home
– Do not take medications that knock you out when you fly so that you cannot get up to stand/stretch
-Try to sit in an emergency exit row for the extra leg space
Finally, understand that for the most part these two causes of swelling typically do not need medical attention and are self-limiting (meaning it goes away by itself).  There is no specific time it is estimated to go away.  Everyone is different.  Do NOT try to take over the counter diuretics.  This could make your situation much worse.  When you should seek medical attention: 
– Swelling is only on one side
– Swelling around the eyes
– Severe dehydration symptoms
– Experiencing any leg pain
– Experiencing any breathing difficulties
– Swelling that gets worse each day even after drinking plenty of fluids
Note:  I am a NSCA certified trainer and a third year medical student, not a M.D., yet.  The information I provided is based upon what I have learned and read from expert resources over the years combined with experience.  Please consult your physician before making any major medical decisions based on this article.